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目 录
一、设计任务
1、专业课程设计题目·················································1 2、专业课程设计任务及设计技术要求···································1 二、炉型的选择······················································1 三、炉膛尺寸的确定··················································1
1、炉膛有效尺寸（排料法）·······································1 1.1确定炉膛内径D ······································ 1 1.2确定炉膛有效高度H ······································· 2 1.3炉口直径的确定············································· 2
1.4炉口高度的确定 ·········································· 3 四、炉体结构设计 ················································ 3
1、炉壁设计 ·················································· 3 2、炉底的设计···················································5 3、炉盖的设计···················································6 4、炉壳的设计···················································7 五、电阻炉功率的确定················································7
1、炉衬材料蓄热量Q蓄7 ········································ 8 2、加热工件的有效热量Q件 ····································· 9
3、工件夹具吸热量Q夹 ········································· 10 4、通过炉衬的散热损失Q散 ······································ 10 5、开启炉门的辐射热损失Q辐 ···································12 6、炉子开启时溢气的热损失Q溢 ··································12 7、其它散热Q它 ··········································· 13 8、电阻炉热损失总和Q总 ··································· 13 9、计算功率及安装功率··········································13 六、技术经济指标计算···············································13
1、电阻炉热效率················································13
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2、电阻炉的空载功率············································14 3、空炉升温时间················································14 七、功率分配与接线方法·············································14
1、功率分配····················································14 2、供电电压与接线方法··········································14 八、电热元件的设计·················································15
1、I区························································15 2、II区··············································16
3.电热元件引出棒及其套管的设计与选择···························18 4.热电偶及其保护套管的设计与选择·······························18
参考书目·······················································19
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一、设计任务 1、专业课程设计题目： 《中温井式电阻炉设计》 2、专业课程设计任务及设计技术要求： 1、φ90×1000中碳钢调质用炉. 2、每炉装16根 3、画出总装图 4、画出炉衬图 5、画出炉壳图（手工） 6、画出电热元件图 7、写出设计说明书 二、炉型的选择 因为工件材料为φ90×1000中碳钢调质用炉对于中碳钢调质最高温度为[870+(30~50)]℃，所以选择中温炉（上限950℃）即可，同时工件为圆棒长轴类工件，因而选择井式炉，并且无需大批量生产、工艺多变，则选择周期式作业。综上所述，选择周期式中温井式电阻炉，最高使用温度950℃。 三、炉膛尺寸的确定 1、炉膛有效尺寸（排料法） 1.1确定炉膛内径D 工件尺寸为φ90×1000,装炉量为16根，对长轴类工件，工件间隙要大于或等于工件直径；工件与料筐的间隙取100~200mm。炉膛的有效高度150~250mm排料法如图所示 则：根据几何关系，每根工件最小距离取90mm，则可以计算出 D=2×90×d=890mm
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D效=d+2×100—200=1100 又因炉壁内径比料筐大200~300mm 故取：D砌=1500mm 查表得可用砌墙砖为 BSL·427·467 (A=168,B=190.8,R=765,r=675)型轻质粘土扇形砖。 由该砖围成的炉体的弧长为： S=?D=3.14×1500=4710mm 砖的块数为：4710÷168=28.04块，取整后N=28 对D进行修正得：D砌=28×168÷3.14=1500mm， 取D砌=1500mm 1.2确定炉膛有效高度H 由经验公式可以得知，井式炉炉膛有效高度H应为所加热元件（或者料筐）的长度的基础上加0.1~0.3m。 H效=1000+200=1200mm H= H效+250=1450mm 由于电阻炉采用三相供电，放置电热元件的搁砖应为3n层， H砌=3n×(65+2)+67,n=6.88.取整后取n=7 再将n=7代入上式，得H砌=1474mm 选用代号为SND-427-09的扇形搁砖 每层搁砖数目为N=?D砌÷50=94.2，取整为94块。 搁砖总数n=94×21=1976块 1.3炉口直径的确定 D效=110mm，由于炉口用斜行楔形砖8SL.427.498 故有，?D效=74×N 将D效=1100mm代入，得N=46.7，取整后N=47，再将N=47代回上式，则得到D炉口=1107mm。 扇形砖选择8SL。427.077 D效=1100mm D砌=1500mm 砖的块数: N=22 修正后： D砌=1500mm 搁砖21层 H砌=1474mm 每层搁砖数目： N=94 搁砖总数 n=1976块 到D炉口=1107mm。 - 2 -
?D炉口 =166×N 得D=20.8取=21
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1.4炉口高度的确定 按一般的设计原则，炉口可由斜行楔形砖和2层直行砖堆砌而成。 故H炉口=（65+2）×3+32=233mm N=21 H炉口=233mm
四、炉体结构设计 炉体包括炉壁、炉底、炉盖、炉壳几部分。炉体通常用耐火层和保温层构成，尺寸与炉膛砌筑尺寸有关。 设计时应满足下列要求： （1）确定砌体的厚度尺寸要满足强度要求，并应与耐火砖、隔热保温砖的尺寸相吻合； （2）为了减少热损失和缩短升温时间，在满足强度要求的前提下，应尽量选用轻质耐火材料； （3）耐火、隔热保温材料的使用温度不能超过允许温度，否则会降低使用寿命； （4）要保证炉壳表面温升小于60℃，否则会增大热损失，使环境温度升高，导致劳动条件恶化。 1、炉壁设计 炉壁厚度可采用计算方法确定，下图为井式炉炉壁二层结构， 第Ⅰ层为耐火层，其厚度一般为90mm，采用轻质粘土砖RNG-0.6； 第Ⅱ层为B级硅藻土砖+耐火纤维，其厚度取标准砖115 mm， 第Ⅲ层为保温层，采用B级硅藻土砖架构中间填充矿渣棉，其厚度设计为x mm。 在稳定传热时，对各炉衬热流密度相同。根据课本的公式结合查表，可得： - 3 -